At present, the forming process of float glass is completed in a tin groove to which protective gas is fed, and is specifically as follows: molten glass continuously flows into the tin groove from a tank furnace and floats on the surface of tin liquor with large relative density, and under the actions of gravity and surface tension, the molten glass is spread, flattened, hardened and cooled on the surface of the tin liquor and is then subjected to annealing and other operations to obtain a flat glass product. In the above forming process of float glass, the glass molten at high temperature floats on the tin liquor, so a certain amount of tin will infiltrate into the lower surface of the glass to turn one surface of the glass into a tin surface.
The tin-infiltrating surface of the float glass has plenty of characteristics capable of influencing further deep processing of the float glass, such as screen printing, membrane coating, curved tempering and large-area flat tempering, therefore, it is quite important to accurately determine the tin surface of the float glass.
The tin in the tin surface of the float glass exists in three valence forms, including Sn0, Sn2+ and Sn4+. The tin element will create an excitation state after absorbing proper light energy. The excitation state, which is unstable, will rapidly decay to a ground state. And the course from the excitation state to the ground state is typically accompanied by photon radiation, i.e. the phenomenon of photoluminescence. Fluorescent light belongs to the phenomenon of photoluminescence of molecules.
A hot cathode gas discharge light tube emitting UV light is mounted inside the commercially available identification devices for the tin surface of float glass currently. In practical application, the tin surface identification device irradiates upwards from the space below the float glass, the hot cathode gas discharge light tube in the tin surface identification device emits UV light, and in accordance with the phenomenon of ultraviolet photoluminescence of the tin element in the float glass, if a surface tightly adhered to the tin surface identification device is the tin surface of the float glass, the tin surface, after being irradiated by the UV light, will rise ultraviolet photoluminescence to emit white fluorescent light, and the white fluorescent light can be seen by human eyes through looking down from the upper surface of the glass; and if the surface tightly adhered to the tin surface identification device is not the tin surface of the float glass, the tin surface will not rise ultraviolet photoluminescence and the white fluorescent light can not be seen by human eyes.
Although the existing tin surface identification device has certain detection effect, the emission of UV light by the hot cathode gas discharge light tube is accompanied by visible light that could cause interference so that the tin surface generates quite unobvious white fluorescent light effect and a detector probably needs to take a long time determining whether the white fluorescent light is generated, as a result, the detection efficiency is dramatically reduced, besides, owing to the harm of the UV light to human body, long-term observation will be adverse to physical health of the detector. Moreover, the process of generating the white fluorescent light by the irradiation of the UV light to the tin surface is transient, so the determination of a detector on the detection result will be impacted if the observation is not in time.
Invention Contents:
Accordingly, the objective of the present invention is mainly to provide an identification device for a tin surface of a float glass, which can improve the identification effect and efficiency for the tin surface of float glass.
In order to reach the objective discussed above, the technical solution of the present invention is implemented in such a manner that:
The present invention provides an identification device for a tin surface of a float glass, comprising: an outer shell, a gas discharge light tube and a power source, the gas discharge light tube and the power source are arranged inside the outer shell, an irradiation window is installed on the outer shell corresponding to the position of the gas discharge light tube, and a UV light-absorbing mark is arranged on the inner or outer surface of the irradiation window.
Further, the gas discharge light tube is a hot cathode gas discharge light tube or a cold cathode gas discharge light tube or a UV light tube.
Further, the gas discharge light tube may be in any shape.
Further, a light filter is further arranged between the gas discharge light tube and the irradiation window.
Further, the UV light-absorbing mark is arranged on the inner or outer surface of the light filter.
Further, the UV light-absorbing mark is arranged on the inner surface of the irradiation window.
Further, the mark is arranged in such a manner of printing, bonding, coating or etching.
Further, the mark may be in any shape, including figure, character, letter, number and the combination thereof.
The UV light-absorbing mark is arranged on the identification device of the present invention, and during the use of the device, owing to the absence of the irradiation of UV light, the tin surface corresponding to the position of the mark emits no white fluorescent light when the tin surface identification device irradiates the tin surface of float glass and, therefore, becomes dark so as to be in sharp contrast with the area of the surrounding, UV light-irradiating tin surface that emits white fluorescent light, hence, a user can see the mark arranged on the float glass directly to obtain more obvious identification effect for the tin surface; in addition, such a manner can avoid using of light filter by eliminating the influence of visible light on the identification result, resulting in simpler structure of the entire device and lowering the cost.
In the present invention, a cold cathode gas discharge light tube can be adopted to take the place of the traditional hot cathode gas discharge light tube, and the service life of the tin surface identification device can be dramatically prolonged because of long service life of the cold cathode gas discharge light tube. Furthermore, the light filter, arranged on the outer shell of the tin surface identification device, is capable of reflecting and absorbing the visible light emitted by the cold cathode gas discharge light tube, thus more obvious effect of white fluorescent light is formed by the tin surface.